12 Replies Latest reply: Sep 19, 2011 10:04 AM by 889055 RSS


      Hi Gurus,

      I have been asked to take an interview for the post of ORACLE DBA.
      This job profile is to support RAC databases.

      I will be questioning DBA's on the following.


      But my main question is how I can judge the DBA about his RAC experience.

          Do you have any experience of RAC yourself? If not, I would suggest that you should get someone with RAC experience to do the interview. Not a very helpful answer, but then you cannot afford to give the responsibility for supporting what are presumably business-critical systems to someone who has just read the relevant Oracle manuals from cover-to-cover.
          • 2. Re: ORACLE RAC INTERVIEW
            Hi Riyadh

            Unless until you have an experience in handling RAC – or at least an overview on RAC you can’t judge the person who got experience on RAC. RAC is very wide!

            • 3. Re: ORACLE RAC INTERVIEW
              kuljeet singh -

              So when u will be arrange interview.................i am intresting....:-) Any way

              For Taking interview, u should have some exp on Rac environment.otherwise u will not be able to find suitable candidate for ur requirement.
              some of the imp points for RAC interview .

              First the person should have Installation exp on linux or solaris and other exp as ..

              installation and Configuration exp on Linux,Solaris or window
              Diff between cluster file system,RAW device and ASM...
              How u can config ur RAC setup on ASM.
              Backup and Recovery policy for RAC setup.....on CFS,RAW device and ASM.
              A good knowlege of RMAN...because from 10g,Rman is the only tool for taking backup of database that are running on ASM.
              TAF,Load Balancing.
              Architecture of RAC,diff Process of RAC
              Cache Fusion.how it works.
              Instance Recovery of RAC....locks....Monitoring of RAC setup.............

              Thanks and Regards
              Kuljeet Pal Singh
              • 4. Re: ORACLE RAC INTERVIEW
                Hi Gurus,

                I am trying to place an sample interview questions.

                First tell me I am right or wrong in my questions and then answer.

                You get only 30 min to answer these question.

                Hear Is your Interview.

                Question:Tune the following RAC DATABASE (DBNAME=PROD) which is 3 node RAC.

                PROD1               PROD2          PROD3
                CPU 8               CPU 15          CPU 8
                32 GB RAM          12 GB RAM     16 GB RAM

                Question: Write a RMAN script for taking backup of the database including arch log files.

                     ARCH LOG LOCATION = /ORACLE/ARCH on each machine.

                Question:Write a sample script for RMAN for the recovery if all the instance are down.(First explain the procedure how you will restore)

                Question: Configure your client TNS so that it connects to PROD3 first then PROD2 and both fails then to prod1.
                     (There will be lot of glitches on the network).

                Please add more questions if you have.

                • 5. Re: ORACLE RAC INTERVIEW
                  Please answer this........................
                  • 6. Re: ORACLE RAC INTERVIEW
                    I am taking a shot at the questions:-
                    Question:Tune the following RAC DATABASE (DBNAME=PROD) which is 3 >node RAC.
                    PROD1 PROD2 PROD3
                    CPU 8 CPU 15 CPU 8
                    32 GB RAM 12 GB RAM 16 GB RAM
                    What are you looking for here? What tuning information do you expect?
                    It is a 3 node cluster with different hardware configuration running RAC.
                    I would put 20% of the memory for Oracle in each node. So that would mean that the SGA is different in each of the nodes.
                    Also since the CPU's are different PROD2 can have more number of max number of processes as compared to the rest of them.

                    But as I said this is just configuration, this is not tuning. Question is not clear.
                    Question: Write a RMAN script for taking backup of the database including arch > log files.
                    ARCH LOG LOCATION = /ORACLE/ARCH on each machine.
                    allocate channel sbt_table .... ;
                    backup database ;
                    backup archive log all delete all input;
                    Question:Write a sample script for RMAN for the recovery if all the instance are > down.(First explain the procedure how you will restore)
                    Bring all nodes down.
                    Start one Node
                    Restore all datafiles and archive logs.
                    Recover 1 Node.
                    Open the database.
                    bring other nodes up.
                    Confirm that all nodes are operational.

                    Some questions from my side:-
                    Q. Clien'ts are performing some operation and suddenly one of the datafile is experiencing problem what do you do?
                    The cluster is a two node one.
                    A. Bring the datafile offline recover the datafile.

                    Q. How can you connect to a specific node in a RAC environment?
                    A. tnsnames.ora ensure that you have INSTANCE_NAME specified in it.

                    Q.What is the difference between a OS cluster and a rac cluster?
                    Look for my post above in this forum.

                    Q.What is gsd?
                    Q. What is cachefusion?
                    Q. What happens when a DML is issued in a RAC environment, how are requests for common buffers handled in a RAC environment.
                    • 7. Re: ORACLE RAC INTERVIEW
                      I'm new to RAC and read a lot about RAC but don't have real time experience. Thanks for sharing this....

                      Thanks Kuldeep & Gopal!!!
                      • 8. Re: ORACLE RAC INTERVIEW
                        Thanks Gopal. I dont have much expereince on , just monitored RAC system for 2 months. Your Q&A gave me more info. If possible provide some more on Tuning RAC systems and Monitoring RAC systems.

                        • 9. Re: ORACLE RAC INTERVIEW
                          Couldn't he also just buy your RAC book ;-)?
                          • 10. Re: ORACLE RAC INTERVIEW
                            RAC interview is interesting topic www.orcl-experts.info povided good information
                            • 11. Re: ORACLE RAC INTERVIEW
                              [Some more Oracle RAC interview questions...|http://dbaregistry.blogspot.com/2010/02/oracle-rac-interview-questions.html] Some more RAC interview questions...

                              • 12. Re: ORACLE RAC INTERVIEW
                                In my opinion always try to ask the concept of RAC and approach towards issues.

                                Edited by: 886052 on 19-Sep-2011 8:04 AM